1. Field of the Invention
The present invention relates generally to compensating devices for use with such as a gun or rifle scope. More specifically, the present invention teaches a combined riflescope and laser rangefinder device incorporating a microprocessor control for establishing a gravitational drop compensation factor for a given projectile trajectory and distance.
2. Description of the Prior Art
The prior art is well documented with gun and rifle scope assemblies, a significant function of which is the combined magnification and targeting of an object (i.e., bull's-eye target, hunting prey, etc.). Moreover, a number of such gun and rifle scope assemblies incorporate a form of range compensating mechanism, such addressing in particular bullet drop over a given trajectory.
U.S. Pat. No. 6,269,581, issued to Groh, teaches a range compensating rifle scope which utilizes laser range-finding and microprocessor technology and in order to compensate for bullet drop over a given trajectory range. The scope includes a laser rangefinder which calculates the distance between the user and the target that is focused in the scope crosshairs. A user enters a muzzle velocity value together with input for bullet weight and altitude, following which the microprocessor calculates a distance that the bullet traveling at the dialed-in speed will drop while traversing the distance calculated by the laser rangefinder, taking into consideration reduced drag at higher altitudes and the weight of the bullet. Based upon this calculated value, a second LCD image crosshair is superimposed in the scope's viewfinder, indicating the proper position at which to aim the rifle in order to achieve a direct hit.
U.S. Pat. No. 4,695,161, issued to Reed, teaches an auto-ranging sight including an optical view exhibiting an LC display reticle and having a plurality of horizontal lines which can be individually selected to be visible. A distance measuring device is provided for measuring distance from the sight to a target. Parameter information is input to a microprocessor to describe the flight of a projectile, the microprocessor also receiving distance information and then determining a required elevation for the optical viewer and attached weapon. The microprocessor selects one of the horizontal lines as the visible horizontal crosshair, upon which the operator then aligns the horizontal and vertical crosshairs seen through the view such that the projectile can be accurately directed to the target. A group of LCD vertical lines can be provided to accommodate windage adjustment for aiming the target. The range determination can be provided by systems using radar, laser, ultrasonic or infrared signals.
U.S. Pat. No. 6,252,706, issued to Kaladgew, teaches a telescopic sight for an individual weapon with automatic aiming and adjustment and which incorporates at least one step micro-motor designed for varying the angle of the sight relative to the axis of the weapon and the initial axis of aim. In this fashion, the whole sight assembly may be varied, thus also varying the original position of the sight reticle from the original point of aim to the required point of aim.
U.S. Pat. No. 5,771,623, issued to Pernstitch et al., teaches a telescopic sight for firearms having a laser rangefinder for the target with a laser transmitter and a laser receiver. Since the beam path of the laser transmitter and the beam path of the laser receiver are brought into the visual telescopic sight beam path, the telescopic sight objective is simultaneously the objective for the laser transmitter and the laser receiver. For adjusting the reticle on the point of impact an optical member is movable relative to the weapon and provided between the reticle and the light entrance side of the telescopic sight.
Finally, U.S. Pat. No. 5,669,174, issued to Teetzel, teaches a laser rangefinder that is modular so that it can be mounted upon different weapon platforms. A pulsed infrared laser beam is reflected off a target and a timed return signal utilized to measure the distance. Another laser, either a visible laser or another infrared laser of differing frequency, is used to place a spot on the intended target. Notch pass optical filters serve to eliminate ambient light interference from the second laser and the range finder uses projectile information stored in the unit to calculate a distance to raise or lower the finger on the weapon.